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Diffstat (limited to 'gas/doc')
| -rw-r--r-- | gas/doc/c-i386.texi | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/gas/doc/c-i386.texi b/gas/doc/c-i386.texi index 869aff6..16640d2 100644 --- a/gas/doc/c-i386.texi +++ b/gas/doc/c-i386.texi @@ -119,6 +119,29 @@ generated. Valid @var{CPU} values are identical to @option{-march=@var{CPU}}. +@cindex @samp{-mmnemonic=} option, i386 +@cindex @samp{-mmnemonic=} option, x86-64 +@item -mmnemonic=@var{att} +@item -mmnemonic=@var{intel} +This option specifies instruction mnemonic for matching instructions. +The @code{.att_mnemonic} and @code{.intel_mnemonic} directives will +take precedent. + +@cindex @samp{-msyntax=} option, i386 +@cindex @samp{-msyntax=} option, x86-64 +@item -msyntax=@var{att} +@item -msyntax=@var{intel} +This option specifies instruction syntax when processing instructions. +The @code{.att_syntax} and @code{.intel_syntax} directives will +take precedent. + +@cindex @samp{-mnaked-reg} option, i386 +@cindex @samp{-mnaked-reg} option, x86-64 +@item -mnaked-reg +This opetion specifies that registers don't require a @samp{%} prefix. +The @code{.att_mnemonic}, @code{.intel_mnemonic}, @code{.att_syntax} and +@code{.intel_syntax} directives will take precedent. + @end table @node i386-Syntax @@ -297,6 +320,23 @@ Far call/jump instructions are @samp{lcall} and @samp{ljmp} in AT&T syntax, but are @samp{call far} and @samp{jump far} in Intel convention. +@section AT&T Mnemonic versus Intel Mnemonic + +@cindex i386 mnemonic compatibility +@cindex mnemonic compatibility, i386 + +@code{@value{AS}} supports assembly using Intel mnemonic. +@code{.intel_mnemonic} selects Intel mnemonic with Intel syntax, and +@code{.att_mnemonic} switches back to the usual AT&T mnemonic with AT&T +syntax for compatibility with the output of @code{@value{GCC}}. +Either of these directives may have an optional argument, @code{prefix}, +or @code{noprefix} specifying whether registers require a @samp{%} prefix. +Several x87 instructions, @samp{fadd}, @samp{fdiv}, @samp{fdivp}, +@samp{fdivr}, @samp{fdivrp}, @samp{fmul}, @samp{fsub}, @samp{fsubp}, +@samp{fsubr} and @samp{fsubrp}, are implemented in AT&T System V/386 +assembler with different mnemonics from those in Intel IA32 specification. +@code{@value{GCC}} generates those instructions with AT&T mnemonic. + @node i386-Regs @section Register Naming |